How to Connect to RDS Instance from AWS Glue Python Shell?

Question

I am trying to access RDS Instance from AWS Glue, I have a few python scripts running in EC2 instances and I currently use PYODBC to connect, but while trying to schedule jobs for glue, I cannot import PYODBC as it is not natively supported by AWS Glue, not sure how drivers will work in glue shell as well.

Answer 1

From: Introducing Python Shell Jobs in AWS Glue announcement:

Python shell jobs in AWS Glue support scripts that are compatible with Python 2.7 and come pre-loaded with libraries such as the Boto3, NumPy, SciPy, pandas, and others.

The module list doesn't include pyodbc module, and it cannot be provided as custom .egg file because it depends on libodbc.so.2 and pyodbc.so libraries.

I think you have 2 options:

1. Create a jdbc connection to your DB from Glue's console, and use Glue's internal methods to query it. This will require code changes of course.
2. Use Lambda function instead. You'll need to pack pyodbc and the required libs along with your code in a zip file. Someone has already compiled those libs for AWS Lambda, see here.

Hope it helps

Answer 2

For AWS Glue use either Dataframe/DynamicFrame and specify the SQL Server JDBC driver. AWS Glue already contain JDBC Driver for SQL Server in its environment so you don't need to add any additional driver jar with glue job.

df1=spark.read.format("jdbc").option("driver", "com.microsoft.sqlserver.jdbc.SQLServerDriver").option("url", url_src).option("dbtable", dbtable_src).option("user", userID_src).option("password", password_src).load()

if you are using a SQL instead of table:

df1=spark.read.format("jdbc").option("driver", "com.microsoft.sqlserver.jdbc.SQLServerDriver").option("url", url_src).option("dbtable", ("your select statement here") A).option("user", userID_src).option("password", password_src).load()

As an alternate solution you can also use jtds driver for SQL server in your python script running in AWS Glue

Answer 3

If anyone needs a postgres connection with sqlalchemy using python shell, it is possible by referencing the sqlalchemy, scramp, pg8000 wheel files, it's important to reconstruct the wheel from pg8000 by eliminating the scramp dependency on the setup.py.

Answer 4

I needed to so something similar and ended up creating another Glue job in Scala while using Python for everything else. I know it may not work for everyone but wanted to mention How to run DDL SQL statement using AWS Glue

Answer 5

I was able to use the python library psycopg2 even though it is not written in pure python and it does not come preloaded with aws glue python shell environment. This runs contrary to aws glue documentation. So you might be able to use odbc related python libraries in a similar way. I created .egg files for psycopg2 library and used it successfully within glue python shell environment. Following are the logs from glue python shell if you have import psycopg2 in your script and the glue job refers to the related psycopg2 .egg files.

Creating /glue/lib/installation/site.py
Processing psycopg2-2.8.3-py2.7.egg
Copying psycopg2-2.8.3-py2.7.egg to /glue/lib/installation
Adding psycopg2 2.8.3 to easy-install.pth file
Installed /glue/lib/installation/psycopg2-2.8.3-py2.7.egg
Processing dependencies for psycopg2==2.8.3
Searching for psycopg2==2.8.3
Reading https://pypi.org/simple/psycopg2/
Downloading https://files.pythonhosted.org/packages/5c/1c/6997288da181277a0c29bc39a5f9143ff20b8c99f2a7d059cfb55163e165/psycopg2-2.8.3.tar.gz#sha256=897a6e838319b4bf648a574afb6cabcb17d0488f8c7195100d48d872419f4457
Best match: psycopg2 2.8.3
Processing psycopg2-2.8.3.tar.gz
Writing /tmp/easy_install-dml23ld7/psycopg2-2.8.3/setup.cfg
Running psycopg2-2.8.3/setup.py -q bdist_egg --dist-dir /tmp/easy_install-dml23ld7/psycopg2-2.8.3/egg-dist-tmp-9qwen3l_
creating /glue/lib/installation/psycopg2-2.8.3-py3.6-linux-x86_64.egg
Extracting psycopg2-2.8.3-py3.6-linux-x86_64.egg to /glue/lib/installation
Removing psycopg2 2.8.3 from easy-install.pth file
Adding psycopg2 2.8.3 to easy-install.pth file
Installed /glue/lib/installation/psycopg2-2.8.3-py3.6-linux-x86_64.egg
Finished processing dependencies for psycopg2==2.8.3

Answer 6

These are the steps that I used to connect to an RDS from glue python shell job:

1. Package up your dependency package into an egg file (these package must be pure python if I remember correctly). Put it in S3.
2. Set your job to reference that egg file under the job configuration > Python library path
3. Verify that your job can import the package/module
4. Create a glue connection to your RDS (it's in Database > Tables, Connections), test the connection make sure it can hit your RDS
5. Now in your job, you must set it to reference/use this connection. It's in the require connection as you configure your job or edit your job.

Once those steps are done and verify, you should be able to connect. In my sample I used pymysql.